US 1640623 A
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Description (OCR text may contain errors)
Aug. '130, 1927. s. F. STEIN BELT'TIGHTENER Filed Jan. 5. 1918 'g' f//////////////A .Illy
Patented ug. 30, 19.27.
Unirse lSTATES Y PATENT, OFFICE.
SAMUEL F. STEIN, OF WILLIAMSPORT, PENNSYLVANIA.
Application led January 5, 1918. Serial No. 210,453.
The driving mechanism of power driven sewing machinesJ includes belts. These belts become loose or slack in use. When as in the case of garmentfactories, a series of machines are driven from one driving shaft and the belt in any one of the series become loose or slack, it is necessary to stopY the running of all the machines of the series, with'consequent loss of valuable time and likelihood of injury or damage to thev goods being worked on, as will be further explained in detail, or as an alternative to stopping all the machines, the workman must run the risk from vrotating shafts or other parts, if he undertakes to remedy the slack condition of the belt without stopping themachines.
The obj ect of my invention is to render unnecessary the stoppage of the machines and thereby avoid the loss of time that comes from stoppage and `at thev same time enable the slack condition of any particular sewing machine belt tof be remedied even by the operative running the machine and without danger of harm or injury from the rotating members.V Under the usual conditions the work of adjusting loose or slack belts is per formed bysome specialmechanic, it being beyond the ability .of the sewing machine operative to do this.
kFor the attainment of my object and to secure other advantages which will be apparent to those skilledjin the art when the embodiment of my invention shown in the drawings is understood, my invention consists in the construction substantially as hereinafter described and claimed. v
In the accompanying drawings:
1 is across section showing a sewing machine power. table construction embodying my invention; y
Fig. 2 is a vertical section on the line 2-2 of Fig. 1. A,
Fig. 3'is a horizontal section on the line 3d?) of Fig. 2;
Fig. 1 is a detail view illustrating ay form of automatic .belt tightener.
Referring to the drawings I show a vdouble power table of ordinary construction, it comprising cast iron supporting legs 10 and two alining parallel series of table tops 11, each adapted to support a sewing machine 12 and having a main driving shaft 13 running longitudinally of the series ofv tables and situated betweenl the two series of tables and beingwdriven continuously by power applied to a band wheel 14 at one end thereof. For
cach sewing machine there is a treadle-controlled transmitter l5 through which power from the continuously running driving shaftv 13 maybe transmitted at the will of the operator .to the' sewing machine, and in the usual practice there is a pulley 16 for each sewmachine on the driving shaft 13 belted to a `pulley on the transmitter by a belt 17 there is a second pulley on the transmitteribelted by a belt 18 to a pulley 19 on the sewing machine shaft adjacent the hand wheel thereof. With such ordinary construction when abelt becomes slack, work on that machine must be stopped and the slack condition remedied by cutting out the surplus portion of the belt and replacing it. Usuallv there is a mechanic whose duty it is to look after such matters, and he, of course, may be busy elsewhere, thus prolonging the disuse of thefmachine, and he must do the work of replacing while the main driving shaft and its pulleys are revolving, and thus is exposedto danger of injury. If, as the safety laws require, all rotating or moving parts which might expose the workman to injury mustY be stopped running, then not only the sewing machine immediately concerned on account of theloose belt, but all ofthe machines that are driven from the same driving shaft are stopped and thus the loss will be multiplied by the number of machines put out of use. The importance and valvek of my invention will 'therefore be seen when it is understood that no stoppage is necessary, but the work of taking. care of al slack belt in a particular machine can be performed while the driving shaft and the other machines are ruiming and without any dan-l yger to the workman concerned doing the work and no special mechanic is required to do the work, but the voperative on the sewing machine can do all that is .necessary to take care of the loose or slack condition." Again the 'matter of stoppage of the sewing machine vis of importance in that if it is prolonged there is. likelihood of injuryy to or damage 'of the goods being sewn. If by reason of the lslack condition of the `belt the machine stops with the work say on a line of stitching partially through the machine it would be exposed to the drip of oilfrom the needle bar land if it should be stationary long enough, enough oil would drip upon it so as to soil or disfigure the goods. By the provision of a belt tightener and especially one capable of adjustment or manipulation by Ahe girl; the belt can always be kept in .a proper tight condition and it' by inadvertcnce or oversight it should become slack and result in stoppage of the machine, the stop need be but momentary because witha belt tightener such as I provide, the slack can at once be taken up and the running of the machine quickly resumed. It the machine stops with the work in it, it would be undesirable to remove the work to prevent injury ifi-om the dropping of oil because of the diiificulty and practical impossibility oit replacing the work in the machine so that the line of stitch. ing would be unbroken.
l provide a belt tightener for the belt 17 which connects the driving shaft 13 with the tiaiisinittei-and said tightener may consist oi' a roller 2O on the lower end of a shank or lstem 21, which passes through a hole in the table top and through a box 22 secured to the upper side of the table top and having 'above the latter a set screw 23 for securing the shank or stem at the desiredvertical position. It will be seen that although the belt to be tightened is below the table top, yet access to the tightener from the top is provided so that conveniently and quickly the necessary adjustment to the tightener may be had without any risk or danger from the running parts of the machinery.
The tightener lor the belt which runs to the sewing machine pulley 19 also consists oiE a belt engaging roller 24 anda shank or bar 25 which carries the same and I also locate said tightener above the table top and mount it upon the side ot the upright portion oi the sewing machine. head so that it is thereby situated for convenient, easy and sate access for manipulation; it is out of the way; and is in el'ect a part of the sewing machine so that if occasion arises 'for moving the sewing machine from the t-able and returning it, the tightener .is always carried by the machine and always in proper position for operat-ioii. I find in many sewing machines the provision of a` threaded hole 26 in the head below the hand wheel and I utilize that hole for the attachment of the tightener to the head. This makes unnecessary the provision ot any special hole and permits of the tightener being applied to machines already in use with no alteration of the machine head or trame. I screw in said hole a. threaded bolt or stud 27, and place over the projecting portion of the stud a spacing block 28 of a thickness whichwill bring the roller-carrying bar in the iight position to secure contact of the roller with the belt, said bar being pivoted on a portion ot said stud which projects beyond the spacing block. Outside ol the block I apply a. wing nut 29 which serves the purpose of clamping the roller-carrying bar at the desired position. Thus one bolt or stud serves as thepivotorr support for the roller-carr.'y}
securing the spacing block.
ing bar andthe means for mounting and The rollercarrying bar instead ot being pivoted to the stud may have a longitudinal slot so that adjustment Jior tightening the belt is effected by a sliding rather than a. swinging move ment.
It will be seen that a very important feature ot my invention is the application ol' a belt tightener to each ot a number ot sewing machines driven from a common shaft because thereby the driving belt in one of the Vmachines which needs adjustment to take up -merely to loosen the wing nut so as to alloiv the spring to act and then to tightenthe wing nut again; or in order to render the device automatic in its action at all times to take up slack or to keep the belt tight', the wing nut may be lett loose or not employed; that is to say a construction may be employed for pivotally attaching the rollercarrying bar not involving the use of a wing nut, in which ca se the stud or bolt 27 may be provided with a slotted head, which may act either as a pivot or as a clamp, by use of a screwl driver, itdesired.
The belt tightener which'l provide for the belt running from the driving shaft may also be made to work automatically by means ot a coil spring 130 by having same connected at one end to the upper end of stem 21 and at the other end to some stationary point'on the table or box 22, as shown in Fig. 4. l i
Having thus'described my invention what l claim is:
l. The combination of the arm of a belt driven sewing mach'ine'having a threaded hole, a stud projecting horizontally from said hole and screwed therein, a constantly acting belt tightener comprising a bar mounted on said stud, and clamping means for said bar.
a 2. The combination of a sewing` machine table; a. sewing machine mountedV thereon; a main driving shatt below 'th'eftable; a transmitter belted -to said driving shaft, .and ineans torA transmitting power from the transmitter to the sewing machine, a belt tightenerextending yfrom belovv the table and reaching'above the table through the tabletop, 1 i' .Tjhe'comhination of. a. sewing machine table, aA sewing. maehineniunted thereon, a
driving shaft, a transmittef under the table diivingly connected to said driving shaftv and belted to the sewing machine and a beltv tightenei" above the table top for the belt running from the tranemittei to the sewing machine and independent 0f the transmitter in its action.
4. 'Ihe Combination of a sewing machine table, a sewing machine mounted thereon, a main driving` shaft, a transmitter under the table belted to said driving shaft and belted to the sewing machine, a belt tightener eX- tending from the belt running from the driving shaft and reaching above the table top, and a belt tightener above the table top for the belt running from the transmitter to the sewing machine and independent of the transmitter in its action.
In testimony that I claim the foregoing I have hereunto set my hand.
SAMUEL F. STEIN.